The science of legislation is an incorrect and misleading expression. Legislation is making laws. We do not talk of the science of making anything. Even the science of government would be an objectionable expression, were it not that government is often loosely taken to signify, not the act of governing, but the state or condition of being governed, or of living under a government. A preferable expression would be, the science of political society; a principal branch of the more extensive science of society, characterized in the text.
One of the strongest reasons for drawing the line of separation clearly and broadly between science and art is the following:—That the principle of classification in science most conveniently follows the classification of causes, while arts must necessarily be classified according to the classification of the effects, the production of which is their appropriate end. Now an effect, whether in physics or morals, commonly depends upon a concurrence of causes, and it frequently happens that several of these causes belong to different sciences. Thus in the construction of engines upon the principles of the science of mechanics, it is necessary to bear in mind the chemical properties of the material, such as its liability to oxydize; its electrical and magnetic properties, and so forth. From this it follows that although the necessary foundation of all art is science, that is, the knowledge of the properties or laws of the objects upon which, and with which, the art dons its work; it is not equally true that every art corresponds to one particular science. Each art presupposes, not one science, but science in general; or, at least, many distinct sciences.
THE END.
(Editor's note)
Essays on some Unsettled. Questions of Political Economy
These five essays represent Mill's earliest thoughts on economic matters and were first composed in 1829 and 1830 before his reputation had been established by the publication of Logic in 1843. Their successful reception no doubt hastened the composition of his comprehensive work the Principles of Political Economy (1848).